Protein kinase B controls transcriptional programs that direct cytotoxic T cell fate but is dispensable for T cell metabolism.

In cytotoxic T cells (CTL), Akt, also known as protein kinase B, is activated by the T cell antigen receptor (TCR) and the cytokine interleukin 2 (IL-2). Akt can control cell metabolism in many cell types but whether this role is important for CTL function has not been determined. Here we have shown that Akt does not mediate IL-2- or TCR-induced cell metabolic responses; rather, this role is assumed by other Akt-related kinases.

Phosphoinositide-dependent kinase 1 controls migration and malignant transformation but not cell growth and proliferation in PTEN-null lymphocytes.

In normal T cell progenitors, phosphoinositide-dependent kinase l (PDK1)-mediated phosphorylation and activation of protein kinase B (PKB) is essential for the phosphorylation and inactivation of Foxo family transcription factors, and also controls T cell growth and proliferation. The current study has characterized the role of PDK1 in the pathology caused by deletion of the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10 (PTEN). PDK1 is shown to be essential for lymphomagenesis caused by deletion of PTEN in T cell progenitors.

Mechanisms of resistance to the cytotoxic effects of oxysterols in human leukemic cells.

We have developed hematopoietic cells resistant to the cytotoxic effects of oxysterols. Oxysterol-resistant HL60 cells were generated by continuous exposure to three different oxysterols-25-hydroxycholesterol (25-OHC), 7-beta-hydroxycholesterol (7beta-OHC) and 7-keto-cholesterol (7kappa-C). We investigated the effects of 25-OHC, 7beta-OHC, 7kappa-C and the apoptotic agent staurosporine on these cells.

Osteoclastic potential of human CFU-GM: biphasic effect of GM-CSF.

Unlabelled: Human osteoclasts can be efficiently generated in vitro from cord blood mononuclear cells and derived CFU-GM colonies. However, CFU-M colonies are poorly osteoclastogenic. Short-term (2-48 h) treatment with GM-CSF stimulates osteoclast formation by proliferating precursors, whereas longer exposure favors dendritic cell formation.

Influence of mode of birth and collection on WBC yields of umbilical cord blood units.

Background: The aim of this study was to determine the influence of mode of birth and umbilical cord blood (CB) collection before (in utero) or after delivery of the placenta (ex utero) on total number of WBCs and CD34+ cells in CB units.

Study Design And Methods: Consecutively donated, banked CB units were assessed for net volume, WBC concentration, total number of WBCs, proportion of CD34+ cells, and total number of CD34+ cells. These parameters were then correlated with the mode of birth and the mode of CB collection relative to the delivery of the placenta.